Mechanical hammer



April 26,1932. R. GOLDSCHMIDT MECHANICAL HAMMER Filed June 17, 1925 VI RM m O w M MM T w m m w 1 m HE R w a w, a WI. l/ll/l/lf/I/ rf/I/ 20 7 5 m w ivy v 2 4 w a Ff H M 4 rw I 6 5 x 4 H ll. m V e e 7 m H7 \Q\M 5 w Patented Apr. 26, 1932.

UNITED STATES PATENT OFFICE RUDOLF GOLDSGHMIDT, OF GHABLOTTENBURG, GERMANY, ASSIGNOB, BY IESHE AB- SIGNMENTS, TO NATHAN KANN, OF NEW YORK, 11'. Y.

MECHANICAL HAMMER Application filed June 17, 1925, Serial No. 87,857, and in. Germany February 17, 1928.

My invention relates to devices for transmitting power and it has special relation to electric hammers.

It is closely related to inventions disclosed in my copending application, filed February 14, 1924, Serial No. 692,873, and to my Patents Nos. 1,410,010, March 21, 1922 and 1,386,329, August 2, 1921, wherein means for changing rotating motion into continuously reciprocating motion has been described.

The method comprises the use of a device embodying rotating weights mounted on a member which is to receive the continuously reciprocating motion.

of the weights provides a component tending to move the hammer, while at the same time a unidirectional force operates on the hammer to provide the continuous movement.

A spring has been used as the means for producing the unidirectional force, which spring was connected to the member itself and to the frame of the device. A second spring was provided between the motor and the driven shaft for purposes of storing energy. The device is subject to very great changes in energy output, and in case of a motor driven hammer, practically all of the stored energy was delivered instantly.

This made it necessary that the energy be supplied by an energy storage means, heretofore constituted by the spring, which spring was put in tension in as uniform manner as possible by the driving motor.

The two springs heretofore used in such devices have an entirely different characteristic than the rotating weights. The centrifugal force of the weights varies in accordance with the square of the speed, while the force of the springs are independent thereof. This has the effect that the operation of the device varies to a great extent by reason of the natural variation of the speed of the motor, which may be caused by voltage variations, and v by changes in the load. This makes it diflicult, in some cases, to maintain the best operating conditions for any length of time.

The object of the present invention is to overcome the foregoing difliculties by replac- 6 ing the spring forces, either that force which The centrifugal force produces the continuous movement or the spring constituting the energy storage device, or both sprmgs, by forces that vary with the speed to the same extent as do the centrifugal forces of the rotating weights. This 1s done by replacin the spring forces by centrifugal .forces 0 rotating weights, whereby these forces will vary with the square of the speed.

Other objects will appear from the following description, read in connection with the accompanying drawings in which:

Figure 1 is a view partially in section and partially in elevation of one embodiment of my invention;

Fig. 2 is a sectional view on the line 11-11 of Fig. 1;

Fig. 3 is a detail view Fig. 4 is a detail view of a modified form of a device for exerting an unidirectional impulse; and Fig. 5 is a cross-sectional view of the hammer employed in my invention.

In the illustrated embodiment of my invention a motor 1 is mounted on a casing 2 and is coupled in driving relation to a guide member 3. The guide member 3 is chambered to receive loosely a hub 4 and a pair of fly weights 5 pivoted to the hub and has slots 6 receiving projections 7 on the fly weights.

, A shaft 8 is slidably and rotatably mounted in the guide member 3 and is keyed for sliding movement in the hub 4.

The rotation of the guide member 3 exerts a centrifugal force on the fly weights 5 tending to move them outwardly radially. As the fly weights 5 are pivoted to the hub 4 the centrifugal force tends to move the shaft forwardly in the direction of rotation. The centrifugal force varies with the square of the speed and therefore on an increase of speed, the tendency to rotate fly weights becomes correspondingly great.

A pair of weighted levers 10 are pivoted to the guide member 3 and are forked to receive the ends of a pair of arms 11 carried on the hub 11 which is slidably and rotatably set on the shaft 8.

The rotation of the guide member 3 exerts 1 a centrifugal force on the levers 10 which is transmitted to the arms 11 and the shaft 8.

produced by the A continuous unidirectional force which is a flilmpttion of the speed is thus exerted on the s a The shaft 8 has .a collar 12 thereon for 5 transmitting the unidirectional force to a sleeve 13 and a hammer 14, rigid with the sleeve, and is j ournaled to rotate in the sleeve and the hammer. A

The hammer carries a pair of lugs 30 having openings therein recelving spring guides 16 which are secured to the casing 1. Weighted gears 17 similar to those described in my above-mentioned atents are mounted for rotation on the sha' 15 and mesh with a pinion 18 rigid with the shaft 8.

The shaft 8 drives the pinion 18 and rotates the gears 17. This causes'the hammer 14 to reciprocate, moving alternately against and with the unidirectional impulse which ed levers 10. The springs 16 yieldingly o ose lateral movement of the shafts 15. Ih ig. 5 I have shown a cross-sectional view of the hammer illustrated in side elevation in Fig. 3. v

In the modification shown in Fig. 4, the weighted levers 20 pivoted to the guide member 3 are also pivoted to weighted levers 21 which in turn are pivotally supported on the shaft 8. The center of gravity of a lever 20 is at a greater distance from the shaft 8 than is the center of gravity of a lever 21.

The modification of 4 operates in a manner similar to that of ig. 1.

' The invention is not limited to the specific details of the embodiments illustrated and described. Diverse modifications are within its scope.

A substantial range of equivalents is contemplated within thescope of the following claims: a Y

I claim as my invention:

1. In a power hammer, the combination of a reciprocatory tool, a rotary drive member, a rotary driven member, a weighted member pivotally mounted on said driving member and movable centrifugally away from the center of rotation thereof, and a member on said driven member adapted to cooperate with said weighted member in all of the positions of said weighted member for the transmission of force from said drive member to said driven member, for impressing unidirectional forces upon said tool.

2. In a power tool, the combination of a reriprocatory tool, a driving member, a driven member to actuate said tool and a weighted member pivoted on said driven member and having a sliding connection with said driving member, said driving member and said weighted member cooperating during the condition of rotation to set up a centrifugal force in said weighted member for causing said driven member to rotate continuously with said driving member, for the development results from the centrifugal force of weight and impression of unidirectional rotative forces on 831d. driven member.

3.-In a power tool, a rotary member, a

weighted member mounted to rotate with said rotary member but movable radially with respect thereto by centrifugal force, a hammer, means operative by the rotation of said rotary member for reciprocating said hammer and means for connecting said weighted member to said hammer for exerting thereon a continuous unidirectional force.

4. In a power tool, the combination of a rotary member, means for rotating said member, a hammer, means operated by said member for transmitting from the first mentioned means to said hammer a continuous unidirectional force, and additional means for reciprocating said hammer.

5. In a power tool, the combination of a rotary member, means for rotating said member, a hammer, means actuated by said r0- tary member for reciprocating said hammer, and a Weighted member pivoted on said rotary member for radial movement and connected to said hammer for exerting a unidirectional force on said hammer.

6. In a'power tool, the combination of a casing, a reciprocatory hammer, rotatable means for imparting reciprocatory forces to said hammer and a pair of yieldable guide members, said rotatable means having a sliding connection with said pair of guide members, whereby said rotatable means may be moved in a predetermined course in said casing, while actuating said reciprocatory hammer.

7. In a power tool, the combination of a hammer, a shaft associated therewith, a Weighted member mounted for rotation on said shaft, means for rotating said weighted member, means operative by the rotation of said weighted member for reciprocating said hammer and a resilient guide member, said shaft having a sliding connection with said guide member, whereby said shaft is guided and its lateral movement limited.

8. In a power tool, the combination of a reciprocatory hammer, a shaft for controlling the operation of said hammer, said shaft projecting on opposite sides of said hammer and a Weighted member mounted for rotation on-said shaft, means for rotating said weighted member for imparting reciprocating forces to said shaft and said hammer and guide members extending through apertures formed in said hammer for yieldingly opposing rotary movement of'said shaft and for guiding said shaft toward and away from said hammer.

In testimony whereof I afiix my signature.

RUDOLF GOLDSCHMIDT. 

